_Artistic license._ To the trained musical individual sounds are heard as different from what a matter-of-fact listener hears. The hearing of pitch, loudness, time, and timbre is not in the ratio of 1:1 with the physical sound, but always runs into artistic analysis and interpretation with artistic license. The musical interval, the dynamic phrasing, the rhythm, and the tone quality are always heard in relation to their artistic setting. Here we find auditory illusions operating in their fullest glory. The pitch value varies with the quality of the sound. Time may be a substitute for stress and vice versa. A subjective rhythm is richer and far more realistic than the physical rhythm. The quality of tone is heard in relation to its musical meaning. To the musician, the hearing is not so much a question of true pitch, formal accent, temporal rhythm, or vowel quality as it is a matter of musical balance and a recognition of artistic deviation from the true. Meticulously exact performance of a Bach score would be musically intolerable. Notes are frail symbols. The performer must interpret even the shortest measure rhythm or single note value. Thus, while fine sensory discrimination in all the aspects of sound is essential for correct hearing and tone production, the more essential thing is his ability to play with artistic power and impulse in hearing and producing artistic balance and artistic deviation from the rigid. In this artistic balance and deviation, he may be guided by certain artistic rules, but his direct emotional interpretation is far more significant. In this lies individuality. He is constantly tempted to be extravagant. Thus, in all the variants, combinations, and modulations of pitch, loudness, time, and timbre, the musician hears, feels, and gives meaning to fine and subtle distinctions, many of them quite divergent from the physical tones. At this level, temperament shows itself in exceedingly fine responsiveness to tones which may be a matter of utter indifference or impossibility to the unmusical. This capacity is largely inborn, both in the way of sensitivity to sound and a general nervous, if not neurotic, disposition, and is in itself enough to make the musician different from other people. Artistic license as a medium for self-expression is, therefore, clear evidence of a musical temperament.